I've sold both in the past. The N804 is a good sounding speaker for the money indeed. It has a bit of warmth to the sound, copared to, say, a more neutral sounding Thiel speaker. It has good dynamics, and even more so when biamped. The Paradigms are musical, and maybe have a smidge less detail, with even more warmth to the sound(even sounding colored with warmth a little). Overall, I find the B&W's more towards neutral than the Pradigms. The Bigger Paradigms may however have a bit more dynamic range and extension...but only a tiny bit I think. If you configure them for "small" for HT dubties at least(which you should by the way), you'll find this a non-issue. Both, played full range for music, would sound very competetive dynamically with a strong amp(I'm not familiar with yours)
As for home theater, both speaker will probably come out pretty close to the same kind of pressentation. They are somewhat of a compromise for HT in a lot of room situations you're likely to put them in. They'll sound more open, laid back, and polite in a large room setting, where you sit further from the speakers, and hear more of the room reflections.
Something to consider if you're a HT buff, is that the Diappolito's, horn speakers, and THX designs tend to be a better chioce for HT dubties overall. Infact, if you look at what all of the magazine reviewers tend to use for their HT systems, you'll see they don't usually go for speakers such as you're considering for HT! There's reasons for this. I've found that the BEST APPLICATION for the type of traditional stereo speaker designs you're considering is in a smaller room environment(which brings other challenges) or where you are proximally sitting closer to the speakers, and hearing more dirrect sound! If you have high ceilings, this is a big benefit with your Paradigm 100 and N804 considerations, and might work just fine for you. Or unless you have good ceiling and also wall acoustic treatment going on in your room, you'll not be so thrilled with the sound...especially for HT.
One sollution, rather than trying to build a "compromise" system between music/HT, would be to get the music speakers you like for 2 channel(unless you're into multi channel music...I'm not), and get some less expensive matching HT speakers that are more effetive for HT dubties! This will not compromise either, and there's a lot of great satalite systems you could chose from.
Another thing might be to consider more HT friendly high end speakers for your system if you're trying to do the "all-in-one" approach. Just take a peak at all the audio mag's out there(i.e, Stereophile GHT mag, HT mag, Widescreen review, Perfect Vision, etc) are using for their HT/music speaker systems, and you'll get a good idea.
I know it's all too easy to get fixated on some traditional stereo speakers you saw in an ad, and that were at the local shop next to your house. But there's potentially a lot more too it.
overall, I would pick the B&W N804's every time over the Pardigms. But then I'm not a huge fan of that line. Even the NHT line is less colored and more neutral. But, tastes varry. I like speakers that are as uncolored and neutral as possible..but that's me.
How big is your room, and what's it like acoustically? This is a HUGE FACTOR in determining what speakers may or may not be the best candidates for your applications/situation.
If you could fill in more info, maybe we could add more info.
Hope this helps